The tradition of citrus jam in Britain is very long. Its origin goes back to the 16th century when Henry VIII received jam as a gift from Portugal. The first printed recipe for this divine substance first appeared in Mary Kettilby's cookbook from 1714. Orange "marmalade," as the British call it, became part of children's literature as the favorite treat of Paddington Bear. Instead of honey, he preferred to eat it on toast with butter.
Some Britons still make it themselves at home. It is something like a ritual and can take up to two days. Every family has its proven recipe, which they do not easily reveal to competitors. It is generally known, however, that jam is best made from very high-quality oranges, with the variety called Seville oranges being the best suited. This type is quite sour, and the peel added to the jam is also more bitter than other varieties, giving the jam its typical taste. It is also important that the peel of commonly available oranges is chemically treated and therefore unsuitable for consumption. It is definitely necessary to use organic quality oranges.
Making jam is not complicated, but as mentioned, it requires quite a bit of time and experience. True British "marmalade" is preserved exclusively with sugar, no chemicals. When cooking the fruit, citrus seeds are also added, which together with the peel contain enough pectin to cause gelation and the proper consistency of the final delicacy. Grapefruits, limes, or other citrus fruits can also be used, depending on the creator's creativity. As the uncrowned "queen of marmalades," Czech Blanka Milfaitová says, jam or preserves can be made from anything. She also has her proven recipe for lemon jam, with which she won the prestigious British World’s Marmalade Awards in 2013 and since then supplies her jams directly to the royal court.
See, and then they say the best orange jam is made by the British!